In the state of the art, the loudspeaker diaphragm is generally attached to the tube-shaped voice coil support with an adhesive. This technique was proven in loudspeakers subjected to a temperature of about 120 degrees Celsius. However, the above named adhesive bonds can no longer be used if loudspeakers must operate reliably at higher than the indicated operating temperatures. Even the use of adhesives that are resistant at higher temperatures is not enough to solve this problem of the mechanically highly stressed joints of voice coil support and loudspeaker diaphragm, since these adhesives are not suited for use above 200 degrees Celsius. Furthermore, the use of such improved, but sometimes also toxic, adhesives can presently no longer be justified for environmental protection reasons.
Although one-piece construction of a loudspeaker diaphragm and a voice coil support are known, they can only be made of plastic or paper/cardboard because of the weight ratios required for this combination. One-piece constructions of light metal, which are accessible to higher operating temperatures as compared to plastic or paper constructions, are presently not available. Tests made by the applicant, to form one-piece aluminum construction of a loudspeaker diaphragm and a voice coil support, have shown that in deep-draw processes, the neck (which serves as voice coil support) with a wall thickness of about 200 .mu.m as required for the diaphragm cone, can only be manufactured to a length of about 10 mm. But such neck lengths are not suitable as voice coil supports. In addition, the 200 .mu.m wall thicknesses of the voice coil supports result in wide air gaps. This lowers the air gap induction and has a negative effect on the temperature stability of the magnet system.